The target was reached after a second cone crusher was installed and the company implemented optimisation initiatives.

In June, the original cone crusher was found to be faulty, which led to a 10-day stoppage and renting of another crusher. BlueRock refurbished the original crusher, which is now operating in tandem with the rented one, increasing throughput capacity.

The company said it would be taking advantage of the high capacity to stockpile material to alleviate production challenges faces during the rainy January-April period.

BlueRock CEO Adam Waugh said continuous production was expected at or above the 80tph level and this put the company in a good position for the remainder of 2018 as it prepared to process kimberlite from the higher grade KV1 pipe, the second of five.

The company started mining at the second kimberlite pipe, KV1, in June, which has an inferred grade of 6.3 carats per hundred tonnes.

The company's broker and nomad SP Angel said the processing development was good news, after years of problems, mishaps and management issues, some of which still need to be resolved.

However, it pointed out that BlueRock would need to ensure the rest of the processing plant could keep up and the two pits could mine above the 80tph rate so a decent sized stockpile could be formed ahead of the wet season.

"If the stars align and management are better able to coordinate mining, crushing and diamond recovery then BlueRock should be worth a multiple of its current capitalisation," SP Angel said.

BlueRock's shares were up 3.59% Friday to 1.01p (US1.3c).